Automatic sprinkler system



AUTOMATIC SPRINKLER SYSTEM Filed Dec. 9. 1924 lNl/ENTOR. IRA \M KN IGHTA TTOR NEWS IRA w. xn'renr, or'onensron,

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RHODE lISLAND, ASSIGNOR T GENERAL FIRE EX- TINGUISHEB COMPANY, OFPROVIDENCE, RHODE ISLAND, A- GQRPORATION @1 DELAWARE.

AUTOMATIC SPRINKLER SYSTEM.

. Application filed December 9, 1924. Serial m. 754,847.

This invention relates to im rovements in automatic sprinkler'systems.ore especially it relates to any dry pipe system having a booster pumpbetween its supply main and 5 its distributing pipes; and particularlythe invention relates to means for automatically startin the pump, asthe need requires and therea ter maintaining its action. These socalledbooster systems provide for sprinkler 10 protection in localities wherethe available supply pressure is or may be inadequate for effectivesprinkler discharge, and are specially'useful when the building itselfis too weak to support the necessary large en tank, and when a pump mustbe avai to boost or build up the low water pressure for supplying thesprinklers when a fire occurs. For starting booster pumps auto-.matically it has been proposed to employ an actuating device whichresponds to a'drop in the system pressure, such as follows the openingof a rinkler. But as the pressure generated by t e pump would promptlyrestore the pressure, some special device is action of the pump.

The present invention provides actuating apparatus which, for startingthe pump, is

responsive to a pressure rise, rather than needed in addition, toinsurethe continuous fall, so that the increase of pressure resultingfrom the pumps action will. act upon the actuating apparatus to maintainthe pump in operation; It is a feature of the invention that, beingresponsive only to rise of pressure, it canbe arranged in atmospherewith no pressure normally exerted upon it.

An embodiment of the invention is illustrated in the accompanyingdrawings in which a circuit closer or a type responsive torise inpressure, is connected with the intermediate chamber of a dry pipevalve. As illustrated this is a difl'erential valve; but the action issuch that it might be applied to any type of dr pipe valve having achamher into which t e water flows, or in which the pressure rises, whenthe valve opens, any such chamber being herein for convenience referredto under the comprehensive term of intermediate chamber. In theillustrated case the chamber is open to atmosphere through a vent of atype well known which becomes closed when the valve opens. Such openingof the valve occurs upon the-giving way of a sprinkler head, withconsequent bleeding of air pressure 1 aid from the ipes. The flow ofwater which follows, lnto the intermediate chamber, produces a ,rise ofressure therein, .which is transmitted to, t e circuit closer andeifects the starting of the pump. The further rise of water pressurewhich follows only adds to the ressure in the closer mechanism andmaintains its status, in position for keepin the pump operatin Itis'intende that the patent shall cover. by suitable expression in theappended claims, whatever features of patentable novelty exist in theinvention disclosed.

In the drawings the single figureis an elevation of a dry pipe systemwith boosterpump and apparatus controlling the same, with the electricalcircuits shown somewhat diagrammatically.

Referring to the drawings, water normally stands at whatever pressuremay occur in the supply main 10 which is assumed to be too low oruncertain for reliance, and is at the same pressure inthe booster pump12, and riser 14 up to the water clapper 16 of a dif* ferential dry pipevalve 18, the pump being still. Beyond the air clapper 20 and dry pipevalve the distributing pipes 22 are filled with air under pressuresufficient to holdtlie valve closed. Sprinkler heads 24 of which thesingle one shown is representative, are distributed about the risk, eachhaving a thermally responsive element adapted to give way upon rise oftemperature to a predetermined point and thus to permit the head to openfor discharge. As the air escapes through the open head, its pressureinthe'pipes falls until it lets the water pressure unseat the dry pipevalve. The clapper 16' lifts'and water flows into the intermediatechamber of the valve, closing the usual vent 26 therefrom and passesthrough branch piping 28 to a circuit closer 30 which is responsiveto'pressure rise to start the pump. In the particular'arrangementindicated by diagram the water pressure closes the switch 32 and thusmakes the circuit from battery 34 through the field winding of asolenoid 36, whose energization draws its armature upward and makes acontact between the terminals 38 of a circuit S controlling'therh'eostat starter 40 which governs a power circuit 44 for operation ofpump motor 42. The pump draws the water from the main 10 and forces itonward at the boosted pressure into the riser 14 and die- .tributingpipes 22 beyond. This incidentally increases the pressure on the circuitclosure 30, but the result is only to maintain the switch 32 closed themore firmly, so that the armature of solenoid 36 is kept in lace acrossthe terminals 38. The current t erefore continues to flow through themotor, and the 'ump will keep ,on supplying pressure unti the rheostatshall be released manually, the svstem drained and reset as initially.

' 1. A sprinkler system having in combination a dry pipe valve, 'a pumpfor boostin the water pressure, and means connecte with the intermediatechamber of said valve and responsive to rise of pressure therein, foreffecting actuation of the .pump upon occurrence of said rise ofpressure.

2. .A sprinkler system having a dry pipe valve with intermediatechamber; a power driven booster pump between the water supply and saidvalve, adapted to increase the pressure of the system; control means forthe power drivmg the ump; and means responslve to lncrease 0 pressure insaid intermediate chamber for actuating said control means to positionfor" driving the pump, thereby automatically to maintain the pump inoperation under influence-of the pressure it creates.

3. A sprinkler system having a dry pipe valve with intermediate chamber;a booster pump adapted to increase the pressure of said system; a motorfor driving said ump; apower circuit for the motor; a r eostatcontrolling said power circuit; anothercircuit governing t e operationof said rheostat; an electromotive device for changing said rheost-atgoverning circuit, comprising an energizing circuit; ,a clrcult closeror said energizing circuit and a pressure controlled device connectedwith the intermediate chamber of the dry pipe valve and adapted uponrise of pressure therein to change the position of said circuit closer,whereby operation of said ump is effected.

Signed ,at Providence,'R ode Island, this 17th day of October, 1924.

IRA W. KNIGHT.

